Double debit on my account when its their financial year end

Good day. I’m still waiting on an answer from MTN regarding the double debit on my account on the 2nd March 2021. I phoned the call centre and spoke to a very arrogant person as my account was double debited . I contacted MTN in February regarding my debit order and I was told that was the debit was correct . To my amazement my account was double debited by MTN when I called the call centre I was told that I never paid in December yet my account was debited in December. So if it wasn’t debited in December why didn’t they debit it in January. 3 months later they debit my account when it’s their financial year end . My account was up to date . So why did they double debit me . I’ve been awaiting a response from the 2nd March already and until now haven’t heard anything. With this pandemic around the world your financial well being is important. Yet they double debit me and can’t give me an answer . This has put a lot of financial difficulty on me due to R1500 being debited extra off my account . Please revert to me as soon. As possible . The same thing happened to me last year May . And even then they never returned my money . So why when you owe them they quick to debit your account . But when they mess up they don’t want to respond with urgency. I’m not happy with this situation.